If you git clone then switch to that branch, you could use the command ./switch_TUI to access the little TUI I made just now to walk you through the evaluation of your iso config under option 2 in the TUI to evaluate (kind of my way to evaluate and dry run until nix stops giving warnings) home manager config and option 15 for the evaluation of the system part of the config (all of the relevant files for this live inside of /system/machine/liveIso and I just connected them in my top-level flake). You’d just have to change filesystem mounts and other hardware related stuff…maybe comment things out until it asks for them then start to open things up again. That’s the beauty of laziness, IMO.
This seems like a worthy endeavor so I worked on it a bit.
Edit: heavily edited to include stuff that I made for you.